PL 06. PDE5: A research odyssey

The discoveries of PDE5, its gene, and its inhibitors are each tortuous. Some of the difficulties were inherently associated with the biological system but others due to inappropriate human conducts. Recognizing these issues - both natural and manmade - may help us perform effective studies and avoid making erroneous interpretations. Examples to be presented include (1) Is PDE5 expressed in the heart, (2) Is PDE5 gene regulated by androgen, (3) Is it possible to generate PDE5 isoform-specific antibodies, (4) Why is PDE5 expressed in the urethral striated muscle, and (5) Can PDE5 inhibitors be "expressed".